Heterogeneity among zymodemes of Leishmania infantum from HIV-positive patients with visceral leishmaniasis in south Italy.

Eleven zymodemes of Leishmania infantum were identified among 38 parasite stocks isolated from Italian HIV-positive patients with visceral leishmaniasis (VL). Only one zymodeme is a common agent of Mediterranean VL in HIV-negative individuals, five zymodemes usually cause simple, self-resolving cutaneous leishmaniasis (CL), and five belong to unique genotypes which have not been previously reported from either VL or CL cases in immunocompetent individuals. This last group of parasites showed reassortment patterns within electromorphs frequently observed in dermotropic L. infantum zymodemes. The highest zymodeme heterogeneity was found in south Italy (Sicily), with six zymodemes identified among 12 HIV-positive patients surveyed.